The Swedish Mammography Cohort, a population based group that includes 61,433 women born between 1914 and 1948 with a median follow-up of 19 years was used to answer the question of whether calcium intake can be harmful? The research team analyzed food intake by questionnaires and estimated the total calcium intake from food and supplements in the study group. Participants were divided into groups based on total daily calcium intake. One group consumed less than 600 mg of calcium per day. A second group consumed between 6000 and 999 mg a day. Group three consumed 1,000 to 1,399 mg per day. The last group consumed more than 1400 mg a day or the equivalent of drinking five 8 ounce glasses of cow’s milk.

The study was led by Karl Michaelsson, MD, of Uppsala University in Sweden and published in the online edition of the British Medical Journal. They found that the group consuming 1400 mg or more per day of calcium had a higher risk of death from cardiovascular disease, ischemic coronary disease and all causes than expected. The high calcium intake did not however increase the risk for strokes. At the other end of the spectrum were those individuals on an extremely low calcium diet with less than 600 mg per day. They were found to have an increased risk of death as well from all the causes mentioned above plus stroke.

Once again this appears to be a call for moderation in one’s diet. Too much or too little of anything is associated with consequences. At the current time postmenopausal women are advised to consume 1600 mg of calcium a day between diet and supplements. It may be time to look at that number and see how it applies to North American women as opposed to Swedish women who participated in this project.